Some comments on the magnetic moments used in REFe₂exchange spring micro-magnetic simulations

Abstract

The current status of magnetic moments used in micro-magnetic modelling of the Laves phase rare earth iron REFe(2) inter-metallic compounds is reviewed. In particular, it is argued that both the neutron scattering results and band structure calculations provide little support for the long-held view that the Fe 3d moments are constant across the REFe(2) series, and for the oft-used rule of thumb that the (57)Fe hyperfine field is proportional to the Fe magnetic moment. Nevertheless, it is argued that it is acceptable to employ a simple ferrimagnetic model, in which the free-ion moment is ascribed to the RE ion and a moment of μ(d) = μ(3d) + μ(5d)≈1.5 µ(B) is used for the combined Fe(3d) and Fe-driven RE(5d) moments.

Magnetic reversal in Dy-dopedDyFe2/YFe2superlattice films

“…This interaction is primarily responsible for the high Curie temperatures. Next in magnitude is the AF Dy-Fe exchange field B Ex (Dy-Fe) ≈ 100 K at T = 0 K. Here we adopt a three-component magnetic model with the Dy, Y, and Fe magnetic moments set at 10μ B , 0μ B , and 1.5μ B , respectively, at T = 0 K [25]. Of course, this model is a gross oversimplification.…”